It’s hot, sticky and miserable. You’ve been outside and you don’t feel well. But do you have Heat Exhaustion, or Heat Stroke? And which is more serious?

The Indiana Department of Homeland Security says both conditions can cause nausea or vomiting. But there are differences between heat exhaustion, which can be dangerous…and heat stroke, which is an emergency.

As the chart shows, victims of heat stroke are often confused, complain of a throbbing headache, and have a rapid, strong pulse. They aren’t sweating and have a body temperature over 103 degrees and their skin is red, hot and dry. They may also lose consciousness.

You should call 9-1-1 immediately if someone is suffering from heat stroke. Be sure to drink plenty of water and limit your outdoor activities during the extreme heat this week.